Water is considered a renewable resource, however, pressures on the resource are growing with increased demands on usage. As the readily available supplies of fresh water are being used up, the importance of water conservation increases. Efforts to conserve water have extended to domestic household use, with much of the focus being on greywater which currently contributes 75% of total wastewater flow to domestic sewers.
Greywater recycling is one method of water conservation. Greywater is waste water that has the potential for reuse. To be considered greywater there must be no human/organic waste (feces) or toxic chemicals. Such sources would include water from normal sink use and shower/bathtub use, or at times used wash water from clothes or dish washing units. This partially used water can be recycled for irrigation or used to flush toilets. With partial filtration, or even with no treatment, greywater can be a valuable and reusable resource.